This Counter64 field reports the frames transmitted per second on the reverse direction of this bidirectional CES tunnel, as computed for this PM instance. Because this is the currently open, still-accumulating measurement interval that keeps climbing until its boundary is reached and it rolls off into the history table, and this specific field is an instantaneous computed rate of transmitted egress traffic rather than a running total, so a spike here shows up the moment it happens rather than only after the interval ends, it is the field to check when you need to see the reverse-direction egress throughput of the tunnel right now rather than a cumulative volume. For example, this counter might read 4,271 frames/sec during the in-progress 15-minute bin — if that number spikes on the reverse side while the opposite direction stays flat, it flags an asymmetric load or fault specific to that leg of the tunnel.